The Astronomical Journal, 150:123 (45pp), 2015 October doi:10.1088/0004-6256/150/4/123 © 2015. The American Astronomical Society. All rights reserved. ON INFRARED EXCESSES ASSOCIATED WITH Li-RICH K GIANTS Luisa M. Rebull1, Joleen K. Carlberg2,7, John C. Gibbs3, J. Elin Deeb4, Estefania Larsen5, David V. Black6, Shailyn Altepeter5, Ethan Bucksbee5, Sarah Cashen3, Matthew Clarke5, Ashwin Datta3, Emily Hodgson3, and Megan Lince3 1 Spitzer Science Center (SSC) and Infrared Science Archive (IRSA), Infrared Processing and Analysis Center (IPAC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125, USA;
[email protected] 2 NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771, USA 3 Glencoe High School, 2700 NW Glencoe Rd., Hillsboro, OR 97124, USA 4 Bear Creek High School, 9800 W. Dartmouth Pl., Lakewood, CO 80227, USA 5 Millard South High School, 14905 Q St., Omaha, NE 68137, USA 6 Walden School of Liberal Arts, 4230 N. University Ave., Provo, UT 84604, USA Received 2015 May 18; accepted 2015 July 2; published 2015 September 28 ABSTRACT Infrared (IR) excesses around K-type red giants (RGs) have previously been discovered using Infrared Astronomy Satellite (IRAS) data, and past studies have suggested a link between RGs with overabundant Li and IR excesses, implying the ejection of circumstellar shells or disks. We revisit the question of IR excesses around RGs using higher spatial resolution IR data, primarily from the Wide-field Infrared Survey Explorer. Our goal was to elucidate the link between three unusual RG properties: fast rotation, enriched Li, and IR excess. Our sample of RGs includes those with previous IR detections, a sample with well-defined rotation and Li abundance measurements with no previous IR measurements, and a large sample of RGs asserted to be Li-rich in the literature; we have 316 targets thought to be K giants, about 40% of which we take to be Li-rich.